Seat device



April 6, 1965 L. HALTER 3,177,036

SEAT DEVICE Filed March 2s, 196:5

United States Patent Oice lih Patented Apr. 6, 1955 naa H1036 SEAT DEVCELudwig Halter, Sommerherg i6, Wildbad, Black Forest, Germany Filed Mar.2S, 1%3, Ser. No. Zd 7 Claims. till. @7n-45d) The present inventionrelates to a seat device adapted to the shape of the body comprising aseat portion and a back restt For an example of a form of seat deviceheretofore reference may be made of my prior latent No. 2,970,63 8,issued February 7, 196i. This patent describes a seat device adapted tothe shape of the body comprising a seat portion and a back rest, saidseat portion being shaped generally to the form of the seat and thighsof a person sitting in normal relaxed position, and the back rest beingshaped generally to the form of the back of a person sitting in normalrelaxed position, said seat portion being provided at its centralportion near the rear of said seat portion with a slightly protrudingarea forming a firm support for the ischium tubers only of the seatedperson, and the back rest being provided with a slightly protruding arealocated centrally of said back rest to form a iirm support for the ossacrurn only of the seated person, whereby the major support of theseated person is by means of the ischium tubers and os sacrum, thedistance of protrusion of said protruding areas being sufficient toassure that the muscular portions of the seat, thighs and back of theseated person bear less heavily on the remaining areas of the seatportion and of the back rest.

in the seat device according to my prior patent, it is presupposed thatcomfortable, natural sitting is only possible if the seat shape pays dueattention to the anatomical requirements of the human body. Thus, thebody must be supported in those portions which are suitable for suchsupport whereas the remaining portions must be correspondingly relievedof load. The seat device according to my prior patent makes provisionfor the most advantageous seated posture (degree of pelvic inclination)and also for the physiological curvature of the vertebral column fromthe posterior, in the sitting posture. The seating posture compelled bythe seat is so selected that, whilst ensuring optimum space fordigestion and respiration, the blood circulation is assisted to themaximum degree and, at the same time, the pelvis and trunk muscularsystem, i.e, the muscular system of the abdomen, pelvis and back, is toa considerable extent relieved of load, but ready to function.

The present invention relates to a further development of the seatdevice according to my prior patent. In the seat device according tothis invention, the support surface in the seat portion has two flat,elongated troughs which are arranged symmetrically with respect to thecentral plane of the seat portion and each of which is adapted toreceive an ischium tuber. These troughs provide a still better means ofsupport for the seated person than is provided by the seat deviceaccording to my prior patent. The troughs prevent the slipping-off ofthe ischium tubers from the support surface therefor and ensure that theseated person will adopt the correct posture.

Seats with curved sitting surfaces are per se not novel. Thus, a seat isknown wherein the sitting surface is higher at the two lateral edgesthan at the other points. This known seat, however, has not got asupport surface associated with the ischium tubers, nor does it provideat elongated troughs arranged symmetrically with respect to the centralplane of the seat, for receiving the ischium tubers. Thus, the effectaccording to the invention cannot be attained with the lmown seat.

In the seat according to the invention, the troughs are advantageouslyrelatively shallow, so that the main function of the support surface inthe seat portion, Le. the support of the ischium tubers, is not lost.

According to a further feature of the invention, the rear end of eachtrough has a gradual incline, while the front end and sides of eachtrough have a steeper inclination.

ln order further to increase the support provided for the ischiumtubers, the lateral edge of the support surface adjacent each troughpreferably projects slightly above the plane of the support surface. Theextent of projection of the lateral edge is conveniently approximately athird of the greatest trough depth.

Advantageously, according to a further feature of the invention, thetroughs, in particular the bottoms of the troughs, are arranged at anacute angle relatively to each other, such angle being open towards theback-rest. This orientation of the troughs suits extremely well theanatomical position of the ischium tubers.

An embodiment of the invention is, by way of example, illustrated in thedrawings, wherein:

FEGURE l is a vertical section through a seat according to theinvention;

FlGURE 2 is a perspective view of the seat according to FIGURE l, seenin the direction of the arrow li; y

FIGURE 3 is an enlarged sectional view of a part of the seat accordingto FIGURE l;

FIGURE 4 is an enlarged plan view of the support surface for the ischiumtubers, showing the troughs; and

FGURE 5 is an enlarged fragmentary sectional view taken along the lineV-V of FGURE 4,

The seat shown in the drawings and indicated generally by the referencel? is of sheet-like form and is made for example of a polyester resinreinforced with glass libres. The seat comprises .a seat portion 2 andan integral baclorest. The back rest ll has formed therein a supportsurface l adapted to support the os Sacrum to whose shape it conforms,whilst the seat portion 2 has formed therein a support surface 3 adaptedto support the ischium tubers.

The support surface 3 has therein two flat elongated troughs 29 arrangedsymmetrically with respect to the central vertical plane of the seat.The lines It; to 2l shown on the support surface 3 in FIGURE 4 arecontour lines connecting points of identical level, the plane of thesupport surface 3 being the reference plane. The line i8 surrounds theentire trough, i.e. is in this reference plane, Whereas the line 2i?approximately indicates the extent of the substantially plane troughbottom, which is of elongate form.

The greater spacing of the lines ld, i9 and Ztl in the rearward zone 2.2of the trough indicates the gradual inclination with which the troughterminates in the rearward zone, whereas the closer spacing of the linesi3, i9 and Ztl at the forward end 23 and at the sides 2d and 25 showsthe steeper inclination of the trough Walls at these points.

The troughs, and in particular the bottom of the troughs, are arrangedat an acute angle relatively to each other, such angle being opentowards the back rest.

The lateral edge 26 of the support surface adjacent the troughs projectsslightly out of the plane of the support surface 3, this being indicatedby the contour line 2li.

The line 27 designates the edge of the support surface 3 externally ofwhich the seat portion 2 declines downwardly. At the rearward end 2.8 ofthe support surface 3, the latter merges in a rounded-off manner intothe back rest l.

The section shown by FEGURE 5 is drawn to a greatly enlarged scale so asto illustrate clearly the shape of a trough 29 and of the adjacentraised lateral edge 26.

The shape of the troughs is such as to suit varying body dimensions.Thus, when the seat is used by someone in which the spacingof theischium tubers from the back Vrest or from the support surface in theback rest is only vof'approximately 12 centimetres and a width ofapproximately centimetres. The remaining plane residual surface 30 onboth sides of the central plane 31 has a width of approximately five tosix centimetres. The entire supporting surface is thus approximatelyeighteen centi-V metres Wide and has a depth of approximately'nineteencentimetres. These dimensions can of course be slightly varied inconformity with anatomical conditions.

I claim as my invention:

1. A seat device adapted to the shape of the body comprising a seatportion and aback rest portion, said seat portion being shaped generallyto the form of the seat and thighs of a person sitting in normal relaxedposition, and the back rest portion being shaped generally to the formof the back of a person sitting in normal relaxed position, said Seatportion being provided at its central portion near the rear of said seatportion with a slightly protruding area forming a firm support for theischiurn tubers only of the seated person, and the seat portion beingprovided with two flat, elongated troughs each of which troughs .isarranged symmetrically with respect to the central plane of the Iseatportion and each of which troughs is adapted to support an ischiumtuber.

2. The seat device as claimed in claim 1, wherein the depth of eachtrough is approximately three millimeters.

3. The seat device as claimed in claim l wherein each trough has alength of approximately twelve centimetres and a width of approximatelylive centimetres and said troughs being spaced apart by a distance ofapproximately five to six centimetres.

4. A seat device adapted to the shape of the body comprosing a seatportion and a back rest portion, said seat portion being shapedgenerally to the form of the seat `and thigh of a person sitting innormal relaxed position, and the back rest portion being `shapedgenerally to the form of the' back of a person sitting in normal relaxedposition, said seat portion being provided at its cent-ral portion nearthe rear of4 said seat portion with a slightly protruding area forming afirm support for the ischium tubers only of the seated person, said seatportion having two Hat, elongated troughs each of which troughs isarranged symmetrically with respect to the central plane ofthe seatportion and each of said troughs being adapted to support an ischiumtuber, the rear end of each trough Vbeing provided with a gradualinclination and the front end and sides of each trough being providedwith a steeper inclination.

5. The seat device as claimed in claim 4, wherein the lateral edge ofsaid seat portion adjacent to each trough projects slightly above theplane of the seat portion.

6. The seat device as claimed in claim 5, wherein said lateral edgeprojectsV above the plane of the lseat portion approximately one-thirdof the greatest trough depth.

7. The seat device as claimed in claim 6, wherein the bottoms of saidtroughs are arranged at an acute angle vwith respect to each other, withsaid Iangles being open towards said back rest portion.

References Cited in the iile of this patent UNITED STATES PATENTS1,716,871 Weldon -a June 11, 1929 2,970,638 Halter Feb. 7, 19613,034,839 Avedon May 15, 1962 3,081,129 Ridder Mar. 12, 1963

1. A SEAT DEVICE ADAPTED TO THE SHAPE OF THE BODY COMPRISING A SEATPORTION AND A BACK REST PORTION, SAID SEAT PORTION BEING SHAPEDGENERALLY TO THE FORM OF THE SEAT AND THIGHTS OF A PERSON SITTING INNORMAL RELAXED POSITION, AND THE BACK REST PORTION BEING SHAPEDGENERALLY TO THE FORM OF THE BACK OF A PERSON SITTING IN NORMAL RELAXEDPOSITION, SAID SEAT PORTION BEING PROVIDED AT ITS RELAXED PORTION NEARTHE REAR OF SEAT PORTION WITH A SLIGHTLY PROTRUDING AREA FORMING A FIRMSUPPORT WITH A SLIGHTLY TUBERS ONLY OF THE SEATES PERSON, AND THE SEATPORTION BEING PROVIDED WITH TWO FLAT, ELONGATED TROUGHS EACH OF WHICHTROUGHS IS ARRANGED SYMMETRICALLY WITH RESPECT TO THE CENTRAL PLANE OFTHE SEAT PORTION AND EACH OF WHICH TROUGHS IS ADAPED TO SUPPORT ANISCHIUM TUBER.